#include "Md5.h"

#include <QString>

#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

/* F, G, H and I are basic MD5 functions. */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
Rotation is separate from addition to prevent recomputation. */
#define FF(a, b, c, d, x, s, ac) { \
 (a) += F ((b), (c), (d)) + (x) + (quint32)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define GG(a, b, c, d, x, s, ac) { \
 (a) += G ((b), (c), (d)) + (x) + (quint32)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
 (a) += H ((b), (c), (d)) + (x) + (quint32)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
 (a) += I ((b), (c), (d)) + (x) + (quint32)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }

MD5::MD5() : isFinalized(false)
{
        context.count[0] = context.count[1] = 0;
        context.state[0] = 0x67452301;
        context.state[1] = 0xefcdab89;
        context.state[2] = 0x98badcfe;
        context.state[3] = 0x10325476;
}

MD5::~MD5()
{
}

MD5 & MD5::update(const QString & str)
{
        uchar *input = (uchar*)str.toAscii().data();
        uint inputLen = str.size();

        uint i, index, partLen;

        /* Compute number of bytes mod 64 */
        index = (unsigned int)((context.count[0] >> 3) & 0x3F);

        /* Update number of bits */
        if((context.count[0] += ((quint32)inputLen << 3)) < ((quint32)inputLen << 3))
                context.count[1]++;
        context.count[1] += ((quint32)inputLen >> 29);

        partLen = 64 - index;

        /* Transform as many times as possible.*/
        if(inputLen >= partLen){
                memcpy((POINTER)&context.buffer[index], (POINTER)input, partLen);
                transform(context.state, context.buffer);

                for(i = partLen; i + 63 < inputLen; i += 64)
                        transform(context.state, &input[i]);

                index = 0;
        }else
                i = 0;
        memcpy((POINTER)&context.buffer[index], (POINTER)&input[i], inputLen-i);
        return(*this);
}

MD5 & MD5::update(uchar *input, uint inputLen)
{
        uint i, index, partLen;

        /* Compute number of bytes mod 64 */
        index = (unsigned int)((context.count[0] >> 3) & 0x3F);

        /* Update number of bits */
        if((context.count[0] += ((quint32)inputLen << 3)) < ((quint32)inputLen << 3))
                context.count[1]++;
        context.count[1] += ((quint32)inputLen >> 29);

        partLen = 64 - index;

        /* Transform as many times as possible.*/
        if(inputLen >= partLen){
                memcpy((POINTER)&context.buffer[index], (POINTER)input, partLen);
                transform(context.state, context.buffer);

                for(i = partLen; i + 63 < inputLen; i += 64)
                        transform(context.state, &input[i]);

                index = 0;
        }else
                i = 0;
        memcpy((POINTER)&context.buffer[index], (POINTER)&input[i], inputLen-i);
        return(*this);
}

const QString MD5::final(void)
{
        if(!isFinalized){
                uchar bits[8];
                uint index, padLen;

                /* Save number of bits */
                encode(bits, context.count, 8);

                /* Pad out to 56 mod 64.*/
                index = (uint)((context.count[0] >> 3) & 0x3f);
                padLen = (index < 56) ? (56 - index) : (120 - index);
                uchar PADDING[64] = {
                        0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
                };
                update(PADDING, padLen);

                /* Append length (before padding) */
                update(bits, 8);

                /* Store state in digest */
                encode(digest, context.state, 16);

                memset((POINTER) &context, 0, sizeof(context));
                isFinalized = true;
        }
        QString ret;
        for(uint i = 0; i < 16; i++){
                ret.append(QString("%1").arg(QString::number(digest[i], 16), 2, '0'));
        }

        return(ret);
}

void MD5::transform(quint32 state[4], uchar block[64])
{
        quint32 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

        decode(x, block, 64);

        /* Round 1 */
        FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
        FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
        FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
        FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
        FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
        FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
        FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
        FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
        FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
        FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
        FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
        FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
        FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
        FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
        FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
        FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

        /* Round 2 */
        GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
        GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
        GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
        GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
        GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
        GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
        GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
        GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
        GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
        GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
        GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
        GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
        GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
        GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
        GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
        GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

        /* Round 3 */
        HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
        HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
        HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
        HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
        HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
        HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
        HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
        HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
        HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
        HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
        HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
        HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
        HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
        HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
        HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
        HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

        /* Round 4 */
        II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
        II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
        II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
        II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
        II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
        II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
        II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
        II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
        II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
        II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
        II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
        II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
        II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
        II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
        II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
        II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

        state[0] += a;
        state[1] += b;
        state[2] += c;
        state[3] += d;

        memset((POINTER)x, 0, sizeof(x));
}

void MD5::encode(uchar *output, quint32 *input, uint len)
{
        uint i, j;

        for(i = 0, j = 0; j < len; i++, j += 4){
                output[j] = (uchar)(input[i] & 0xff);
                output[j+1] = (uchar)((input[i] >> 8) & 0xff);
                output[j+2] = (uchar)((input[i] >> 16) & 0xff);
                output[j+3] = (uchar)((input[i] >> 24) & 0xff);
        }
}

void MD5::decode(quint32 *output, uchar *input, uint len)
{
        unsigned int i, j;

        for(i = 0, j = 0; j < len; i++, j += 4)
                output[i] = ((quint32)input[j]) | (((quint32)input[j+1]) << 8) | (((quint32)input[j+2]) << 16) | (((quint32)input[j+3]) << 24);
}

void MD5::memcpy( POINTER output, POINTER input, uint len )
{
        uint i;

        for (i = 0; i < len; i++)
                output[i] = input[i];
}

void MD5::memset(POINTER output, int value, uint len)
{
        unsigned int i;

        for (i = 0; i < len; i++)
                ((char *)output)[i] = (char)value;
}
